This invention relates to a suction cup having a proximity sensor which is isolated from the vacuum chamber in a part handling tool.
Suction cups are utilized in many applications for moving parts in a factory setting. A suction cup communicates with a source of vacuum to provide a lifting force for lifting a part. As an example, suction cups are utilized with moving tools for grabbing and then moving sheet materials.
One challenge in the use of suction cups in such settings is insuring that a part has been lifted and is being moved. It is thus desirable to incorporate a sensor for sensing the presence of a part adjacent to the cup. Cups have been proposed wherein a vacuum chamber surrounds a sensor which is in the vacuum cup. These systems have some deficiencies in that it would be desirable to isolate the sensor from the vacuum chamber for a number of reasons. One reason is that with the sensor in the vacuum cup, the sealing of the sensor mount must be precise and fluid tight. Otherwise, the vacuum could be broken. Moreover, with such systems the vacuum cup is relatively large as is the vacuum chamber. This requires a solid surface on the part to be lifted.
In the disclosed embodiment of this invention, a vacuum cup is utilized which has radially inner and outer lips to define a vacuum chamber. A sensor is mounted interior to the radially inner lip of the cup. The inner lip isolates the sensor from the vacuum chamber.
Thus, the sensor need not have a fluid tight seal. Moreover, the vacuum cup is relatively small, and thus holes or openings within the part to be lifted will not break the vacuum cup.
In a preferred embodiment the inner and outer lips of the cup extend for approximately equal distances from a mount portion.